# P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx re ductions from EERP\HTC BART NOx Reduction Memo 2007 -12-10 FINAL.doc



# Memorandum

To: Andrea Hayden – Hibbing Taconite Company (HTC)

From: Erik Boleman

Subject: BART NO

x 

# Emission Reduction Analysis

Date: December 10, 2007

Project: 23/69-A60-002

c: Beth Havlik – Barr Engineering

Andrew Skoglund – Barr Engineering

This memo summarizes the analysis which was conduct ed for the NO

x 

# emission reductions which

occurred due to the energy efficiency projects for the three indurating furnaces at your facility. Thi s

document presents the following information:

• Stack test data,

• Emission reduction calculations,

• Stack parameters (flow and temperature),

• Visibility modeling overview, and

• Summary of visibility modeling results.

Stack Test Data

Stack tests were conducted on each indurating furna ce before and after the energy efficiency projects.

The raw data are presented is tables 1, 2, and 3.

Emission Reduction Calculations

Barr has calculated the NO

x 

# emissions based on the stack test data presented i n tables 1, 2, and 3. We

determined the NO

x 

# emission reductions in units of pounds of NO

x 

# per dry long ton of pellets produced

(lb/dlt). It is important to note that the MPCA mo deling protocol modeled each furnace as a single st ack

rather than four separate stacks. Therefore, we ca lculated an average emission reduction for each

furnace, applied the emission reduction to the maxi mum emission rate from the baseline conditions as

presented in the BART report, and calculated new em ission rates for the visibility impacts modeling of

the current operation.

The emission calculations are presented in table 4, 5, and 6. A summary is provided in table 7.

Stack Parameters (Flow and Temperature)

Air dispersion modeling of the NOx emission reducti ons from the energy efficiency projects was

conducted using two separate scenarios for stack pa rameters. The air dispersion modeling for Scenario A

was conducted using the same stack parameters as th e baseline conditions.

However, the air dispersion modeling for Scenario B uses new stack parameters which are based on the

recent stack test results, because the stacks’ temp erature and flow appear to have changed due to the

energy efficiency projects. As previously stated, the MPCA modeling protocol modeled each furnace as

Barr Engineering Company

332 West Superior Street, Suite 600 • Duluth, MN 55802

Phone: 218-727-5218 • Fax: 218-727-6450 • www.barr.com An EEO Employer



# Minneapolis, MN • Hibbing, MN • Duluth, MN • Ann Arbor, MI • Jefferson City, MO

# To: Andrea Hayden – HTC

From: Erik Boleman – Barr Engineering

Subject BART NOx Emission Reduction Analysis

Date: December 10, 2007

Page: 2 of 2



# a single stack rather than four separate stacks. T herefore, Barr calculated the Scenario B stack flow rates

by calculating the average flow rate from the four stacks. The Scenario B stack temperatures were

calculated as the maximum temperature of the four s tacks, which appears to be consistent with the

baseline temperature as selected by MPCA.

The stack flow rate and temperature calculations an d comparisons are presented in Table 8.

Visibility Modeling Overview

Two post-BART emissions scenarios were modeled. Th e additional modeling followed the same

procedures described in Appendices B and C of the o riginal report.

Predicted Stack Parameters and 24-Hour Maximum Emis sion Rates

Pursuant to guidance from MPCA and to be consistent with use of the highest daily emissions for

pre-BART visibility impacts, the post-BART emission s to be used for the visibility impacts analysis

reflect a maximum 24-hour average basis. Table 9 presents the post-BART model input parameters.

Modeled Results

Visibility impairment was modeled using the meteoro logical data for the years 2002, 2003 and 2004

for the predicted post-BART emission scenario(s). R esults for the 98th percentile and number of days

above 0.5 dV at Boundary Waters Canoe Area Wilderne ss (BWCA) and Voyageurs National Park

(VNP) are included in Table 10.

Summary of Visibility Modeling Results

Using the modeling procedure as described above, th e energy efficiency projects resulted in visibility

improvement compared to the baseline (pre-BART) ope rating conditions as follows:

• Modeled 98 th 

# Percentile: Baseline value was 1.609 deciview (dV). Scenario A (baseline

stack parameters) resulted in a visibility improvem ent on the 98 th 

# percentile day of

approximately 0.690 dV or 43%. Scenario B (stack p arameters based on the latest stack test)

resulted in a visibility improvement on the 98 th 

# percentile day of approximately 1.104 dV or

69%.

• Number of Days Over 0.5 dV: Baseline value was 189 days. Scenario A (baseline stack

parameters) resulted in a decrease the number of da ys over 0.5 dV of 106 days or 56%.

Scenario B (stack parameters based on the latest st ack test) resulted in a decrease in the

number of days over 0.5 dV of 168 days or 89%.Table 1: HTC Stack Test Data - Line 1 (EU 020)GE Report M22A0346BVent IDRun Num1 2 3 Ave 1 2 3 Ave 1 2 3 Ave 1 2 3 AveDate5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007 5/1/2007Temp (°F)93 93 95 93.7 95 93 94 94.0 102 102 102 102.0 117 113 113 114.3Moisture (Bws)0.04 0.04 0.04 0.040 0.04 0.04 0.05 0.043 0.09 0.08 0.09 0.0870.07 0.08 0.07 0.073Volume Flow Rate (ACFM)194,581 194,762 194,855 194,733 193,671 187,146 190,177 190,331 217,628 217,001 218,241 217,623 184,834 184,755 184,532 184,707Nox Conc (ppmd)32.6 31.2 35.8 33.2 58.2 57.5 65.8 60.5 92.4 96.3 93.4 94.0 105.3 98.9 97.8 100.7Nox Emission (lb/hr)41.37 39.54 45.41 42.1 73 69.9 80.18 74.4 85.17 88.9 86.21 86.8 118.31 110.51 110.07 113.0Production (dlt/hr)370 373 371 371.3 371 372 372 371.7 371 371 365 369.0 372 365 351362.7MMBtu/hr78 73 88 79.7 78 72 100 83.3 82 86 104 90.7 102 89 92 94.3Barr Project 2369951TAKVent IDRun Num1 2 3 Ave 1 2 3 Ave 1 2 3 Ave 1 2 3 AveDate6/14/2005 6/14/2005 6/14/2005 6/15/2005 6/15/2005 6/15/2005 6/15/2005 6/16/2005 6/16/2005 6/16/2005 6/16/2005 6/16/2005Temp (°F)96 96 96 96.0 99 99 101 99.7 106 105 106 105.7 111 111 109 110.3Moisture (Bws)0.061 0.061 0.061 0.061 0.063 0.065 0.069 0.066 0.082 0.079 0.079 0.080 0.092 0.092 0.086 0.090Volume Flow Rate (ACFM)202,000 202,000 204,000 202,667 201,000 201,000 201,000 201,000 189,000 187,000 181,000 185,667 187,000 179,000 181,000 182,333Nox Conc (ppmd)71 69 66 68.7 98 95 101 98.0 159 148 156 154.3 181 183 185 183.0Nox Emission (lb/hr)85 83 81 83.0 118 114 120 117.3 173 162 165 166.7 194 187 193 191.3Production (dlt/hr)347 344 341 344.0 348 350 352 350.0 350 351 351 350.7 351 351 352351.3MMBtu/hr127 127 124 126.0 127 127 128 127.3 128 127 127 127.3 127 125 124125.3SV 021SV 022SV 023SV 024SV 021SV 022SV 023SV 024P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx reductions from EERP\HTC NOx Reduction Calcs 2007-12-06 FINALTab 1 - Line 1 DATA12/11/2007Table 2: HTC Stack Test Data - Line 2 (EU 021)GE Report M22A0346BVent IDRun Num123Ave123Ave123Ave123AveDate5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007 5/2/2007Temp (°F)106 107 110 107.7 103 101 102 102.0 96 96 97 96.3 89 90 92 90.3Moisture (Bws)0.07 0.07 0.08 0.073 0.06 0.07 0.06 0.063 0.07 0.07 0.07 0.0700.06 0.06 0.06 0.060Volume Flow Rate (ACFM)172,058 170,048 169,343 170,483 180,846 178,533 189,663 183,014 184,879 183,993 182,729 183,867 193,718 194,934 194,815 194,489Nox Conc (ppmd)104.2 109.4 114.3 109.3 105.3 104.7 100.5 103.5 67.8 67.8 68.7 68.1 52.6 52.3 53.8 52.9Nox Emission (lb/hr)110.77 115.31 118.4 114.8 119.84 117.57 120.58 119.3 79.44 79.18 79.43 79.4 65.63 65.59 67.53 66.3Production (dlt/hr)344 362 359 355.0 363 363 358 361.3 364 366 375 368.3 360 369 375368.0MMBtu/hr96 101 103 100.0 104 104 104 104.0 104 104 106 104.7 104 102 104 103.3Barr Project 2369870TAKVent IDRun Num123Ave123Ave123Ave123AveDate6/23/2004 6/23/2004 6/23/2004 6/23/2004 6/23/2004 6/23/2004 6/22/2004 6/23/2004 6/23/2004 6/22/2004 6/22/2004 6/22/2004Temp (°F)117 116 116116.3109 110 111110.0100 99 9999.398 96 9696.7Moisture (Bws)0.096 0.089 0.0940.0930.079 0.078 0.0780.0780.068 0.052 0.0540.0580.052 0.055 0.0550.054Volume Flow Rate (ACFM)191,000 190,000 194,000 191,667 192,000 194,000 193,000 193,000 204,000 205,000 206,000 205,000 206,000 206,000 204,000 205,333Nox Conc (ppmd)139 134 136136.3123 117 117119.084 83 8584.065 63 6564.3Nox Emission (lb/hr)148 143 148146.3136 133 130133.0102 103 106103.781 79 8080.0Production (dlt/hr)367 370 368368.3368 369 365367.3366 363 364364.3365 365 365365.0MMBtu/hr106 111 108108.3106 106 105105.7110 108 108108.7108 109 110109.0SV 025SV 026SV 027SV 028SV 025SV 026SV 027SV 028P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx reductions from EERP\HTC NOx Reduction Calcs 2007-12-06 FINALTab 2 - Line 2 DATA12/11/2007Table 3: HTC Stack Test Data - Line 3 (EU 022)GE Report M22A0346BVent IDRun Num123Ave123Ave123Ave123AveDate5/8/2007 5/8/2007 5/8/2007 5/8/2007 5/8/2007 5/8/2007 5/7/2008 5/8/2007 5/8/2007 5/7/2007 5/7/2007 5/7/2007Temp (°F)97 98 97 97.3 101 102 103 102.0 115 111 113 113.0 123 123 120 122.0Moisture (Bws)0.08 0.1 0.07 0.083 0.08 0.08 0.09 0.083 0.07 0.06 0.08 0.070 0.06 0.06 0.08 0.067Volume Flow Rate (ACFM)202,928 207,393 208,374 206,232 207,291 207,604 201,264 205,386 194,503 199,996 188,072 194,190 201,346 202,366 200,712 201,475Nox Conc (ppmd)33.8 32.4 30.8 32.3 46.8 47 48.7 47.5 69.4 68.5 68.6 68.8 100.997.2 102.7 100.3Nox Emission (lb/hr)42.47 40.63 39.85 41.0 59.31 59.49 59.48 59.4 82.08 83.93 83.1 83.0 122.55 118.57 121.86 121.0Production (dlt/hr)373 378 370 373.7 373 360 375 369.3 377 372 361 370.0 376 377 375376.0MMBtu/hr104 104 104 104.0 104 104 104 104.0 102 108 108 106.0 102 103 104103.0Barr Project 2369951TAKVent IDRun Num123Ave123Ave123Ave123AveDate6/22/2005 6/23/2005 6/23/2005 6/21/2005 6/21/2005 6/21/2005 6/21/2005 6/21/2005 6/21/2005 6/20/2005 6/20/2005 6/20/2005Temp (°F)97 101 103100.3103 103 104103.3115 114 116115.0120 120 120120.0Moisture (Bws)0.062 0.064 0.0690.0650.07 0.074 0.0650.0700.09 0.078 0.1040.0910.111 0.116 0.1140.114Volume Flow Rate (ACFM)206,000 209,000 208,000 207,667 207,000 212,000 211,000 210,000 209,000 209,000 217,000 211,667 199,000 196,000 196,000 197,000Nox Conc (ppmd)68 67 6165.386 87 8887.0138 137 141138.7158 155 158157.0Nox Emission (lb/hr)85 83 7581.0105 109 111108.3164 165 171166.7173 167 170170.0Production (dlt/hr)383 381 377380.3380 381 381380.7378 373 381377.3375 374 374374.3MMBtu/hr119 121 119119.7116 117 115116.0116 115 115115.3117 116 116116.3SV 029SV 030SV 031SV 032SV 029SV 030SV 031SV 032P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx reductions from EERP\HTC NOx Reduction Calcs 2007-12-06 FINALTab 3 - Line 3 DATA12/11/2007

# Table 4: HTC NOx Emission Reduction Calculations - Line 1 (EU 020)

SV 021 SV 022 SV 023 SV 024 Total

Temperature (*F)

Baseline 96.0 99.7 105.7 110.3 ---

Post EERP 93.7 94.0 102.0 114.3 ---



# Change -2.3 -5.7 -3.7 4.0 NA

-2.4% -5.7% -3.5% 3.6% NA



# Stack Flow Rate (acfm)

Baseline 202,666.7 201,000.0 185,666.7 182,333.3 ---

Post EERP 194,732.7 190,331.3 217,623.3 184,707.0 ---



# Change -7,934.0 -10,668.7 31,956.6 2,373.7 NA

-3.9% -5.3% 17.2% 1.3% NA



# Production (dlt/hr)

Baseline 344.0 350.0 350.7 351.3 ---

Post EERP 371.3 371.7 369.0 362.7 ---



# Change 27.3 21.7 18.3 11.4 NA

7.9% 6.2% 5.2% 3.2% NA



# Natural Gas (MMBtu/hr)

Baseline 126.0 127.3 127.3 125.3 ---

Post EERP 79.7 83.3 90.7 94.3 ---



# Change NA NA NA NA NA

NA NA NA NA NA



# NOx (lb/hr)

Baseline 83.0 117.3 166.7 191.3 ---

Post EERP 42.1 74.4 86.8 113.0 ---



# Change NA NA NA NA NA

NA NA NA NA NA



# Natural Gas (MMBtu/dlt)

Baseline 0.366 0.364 0.363 0.357 1.450

Post EERP 0.215 0.224 0.246 0.260 0.945



# Change -0.151 -0.140 -0.117 -0.097 -0.505

-41.3% -38.5% -32.2% -27.2% -34.8%



# NOx (lb/dlt)

Baseline 0.241 0.335 0.475 0.545 1.596

Post EERP 0.113 0.200 0.235 0.312 0.860



# Change -0.128 -0.135 -0.240 -0.233 -0.736

-53.1% -40.3% -50.5% -42.8% -46.1%



# Reductions for Regional Haze Modeling

NOx Emission Reduction (%) -46.1%

P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx re ductions from EERP\HTC NOx Reduction Calcs 2007-12- 06 FINAL

Tab 4 - Line 1 CALCS 12/11/2007

# Table 5: HTC NOx Emission Reduction Calculations - Line 2 (EU 021)

SV 025 SV 026 SV 027 SV 028 Total

Temperature (*F)

Baseline 116.3 110.0 99.3 96.7 ---

Post EERP 107.7 102.0 96.3 90.3 ---



# Change -8.6 -8.0 -3.0 -6.4 NA

-7.4% -7.3% -3.0% -6.6% NA



# Stack Flow Rate (acfm)

Baseline 191,666.7 193,000.0 205,000.0 205,333.3 ---

Post EERP 170,483.0 183,014.0 183,867.0 194,489.0 ---



# Change -21,183.7 -9,986.0 -21,133.0 -10,844.3 NA

-11.1% -5.2% -10.3% -5.3% NA



# Production (dlt/hr)

Baseline 368.3 367.3 364.3 365.0 ---

Post EERP 355.0 361.3 368.3 368.0 ---



# Change -13.3 -6.0 4.0 3.0 NA

-3.6% -1.6% 1.1% 0.8% NA



# Natural Gas (MMBtu/hr)

Baseline 108.3 105.7 108.7 109.0 ---

Post EERP 100.0 104.0 104.7 103.3 ---



# Change NA NA NA NA NA

NA NA NA NA NA



# NOx (lb/hr)

Baseline 146.3 133.0 103.7 80.0 ---

Post EERP 114.8 119.3 79.4 66.3 ---



# Change NA NA NA NA NA

NA NA NA NA NA



# Natural Gas (MMBtu/dlt)

Baseline 0.294 0.288 0.298 0.299 1.179

Post EERP 0.282 0.288 0.284 0.281 1.135



# Change -0.012 0.000 -0.014 -0.018 -0.044

-4.1% 0.0% -4.7% -6.0% -3.7%



# NOx (lb/dlt)

Baseline 0.397 0.362 0.285 0.219 1.263

Post EERP 0.323 0.330 0.216 0.180 1.049



# Change -0.074 -0.032 -0.069 -0.039 -0.214

-18.6% -8.8% -24.2% -17.8% -16.9%



# Reductions for Regional Haze Modeling

NOx Emission Reduction (%) -16.9%

P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx re ductions from EERP\HTC NOx Reduction Calcs 2007-12- 06 FINAL

Tab 5 - Line 2 CALCS 12/11/2007

# Table 6: HTC NOx Emission Reduction Calculations - Line 3 (EU 022)

SV 029 SV 030 SV 031 SV 032 Total

Temperature (*F)

Baseline 100.3 103.3 115.0 120.0 ---

Post EERP 97.3 102.0 113.0 122.0 ---



# Change -3.0 -1.3 -2.0 2.0 NA

-3.0% -1.3% -1.7% 1.7% NA



# Stack Flow Rate (acfm)

Baseline 207,666.7 210,000.0 211,666.7 197,000.0 ---

Post EERP 206,231.7 205,386.3 194,190.3 201,474.7 ---



# Change -1,435.0 -4,613.7 -17,476.4 4,474.7 NA

-0.7% -2.2% -8.3% 2.3% NA



# Production (dlt/hr)

Baseline 380.3 380.7 377.3 374.3 ---

Post EERP 373.7 369.3 370.0 376.0 ---



# Change -6.6 -11.4 -7.3 1.7 NA

-1.7% -3.0% -1.9% 0.5% NA



# Natural Gas (MMBtu/hr)

Baseline 119.7 116.0 115.3 116.3 ---

Post EERP 104.0 104.0 106.0 103.0 ---



# Change NA NA NA NA NA

NA NA NA NA NA



# NOx (lb/hr)

Baseline 81.0 108.3 166.7 170.0 ---

Post EERP 41.0 59.4 83.0 121.0 ---



# Change NA NA NA NA NA

NA NA NA NA NA



# Natural Gas (MMBtu/dlt)

Baseline 0.315 0.305 0.306 0.311 1.237

Post EERP 0.278 0.282 0.286 0.274 1.120



# Change -0.037 -0.023 -0.020 -0.037 -0.117

-11.7% -7.5% -6.5% -11.9% -9.5%



# NOx (lb/dlt)

Baseline 0.213 0.284 0.442 0.454 1.393

Post EERP 0.110 0.161 0.224 0.322 0.817



# Change -0.103 -0.123 -0.218 -0.132 -0.576

-48.4% -43.3% -49.3% -29.1% -41.3%



# Reductions for Regional Haze Modeling

NOx Emission Reduction (%) -41.3%

P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx re ductions from EERP\HTC NOx Reduction Calcs 2007-12- 06 FINAL

Tab 6 - Line 3 CALCS 12/11/2007

# Table 7: HTC NOx Emission Reduction Summary

Line 1

EU 020 Line 2

EU 021 Line 3

EU 021

NOx (lb/dlt)

Baseline 1.596 1.263 1.393

Post EERP 0.860 1.049 0.817



# Change -0.736 -0.214 -0.576

-46.1% -16.9% -41.3%



# Reductions for Regional Haze Modeling

NOx Emission Reduction (%) -46.1% -16.9% -41.3%

P:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx re ductions from EERP\HTC NOx Reduction Calcs 2007-12- 06

FINAL

Tab 7 - NOx Summary 12/11/2007Table 8: HTC Stack Flow Rate and Temperature ComparisonsLine 1 - EU 020Post EERP Flow SV 021 SV 022 SV 023 SV 024Scenario B* Scenario 0 + A**Stack Flow (acfm) 194,732.7 190,331.3 217,623.3 184,707.0Stack Diameter (inches) 104.5 104.5 104.5 104.5Stack Area (ft^2) 59.5 59.5 59.5 59.5Stack Velocity (ft/min) 3,271.1 3,197.2 3,655.7 3,102.7Stack Velocity (m/s) 16.6 16.2 18.6 15.8 16.8 16.1Stack Temp (*F)Post EERP93.7 94.0 102.0 114.3 114 120Line 2 - EU 021Post EERP Flow SV 025 SV 026 SV 027 SV 028Scenario B* Scenario 0 + A**Stack Flow (acfm) 170,483.0 183,014.0 183,867.0 194,489.0Stack Diameter (inches) 104.5 104.5 104.5 104.5Stack Area (ft^2) 59.5 59.5 59.5 59.5Stack Velocity (ft/min) 2,863.8 3,074.3 3,088.6 3,267.0Stack Velocity (m/s) 14.5 15.6 15.7 16.6 15.6 16.6Stack Temp (*F)Post EERP107.7 102.0 96.3 90.3 108 120Line 3 - EU 022Post EERP Flow SV 029 SV 030 SV 031 SV 032Scenario B* Scenario 0 + A**Stack Flow (acfm) 206,231.7 205,386.3 194,190.3 201,474.7Stack Diameter (inches) 104.5 104.5 104.5 104.5Stack Area (ft^2) 59.5 59.5 59.5 59.5Stack Velocity (ft/min) 3,464.3 3,450.1 3,262.0 3,384.4Stack Velocity (m/s) 17.6 17.5 16.6 17.2 17.2 17.3Stack Temp (*F)Post EERP97.3 102.0 113.0 122.0 122 120* Scenario B: Stack Flow = average of 4 stacks; Stack Temperature = maximum of 4 stacks (appears to beconsistent with baseline temperature selection)** Scenario 0 + A: Stack Flow and Stack Temperatureas modeled as baseline conditions in 2006 BART ReportP:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx reductions from EERP\HTC NOx Reduction Calcs 2007-12-06 FINALTab 8 - Stack Flow + Temp12/11/2007SO2 NOx% reduct.Max 24-hrlb/day % reduct.Max 24-hrlb/day0Base(Wet PM Scrubbers)Base(Max = gas)EU 020 Line 116.11 322 --- 720 --- 13,392EU 021 Line 216.59 322 --- 912 11,112EU 022 Line 317.26 322 --- 1,032 --- 12,624ABase(Wet PM Scrubbers)Energy EfficiencyProjects(no stack changes)EU 020 Line 1 Current operations -46.1% 16.11 322 --- 720 46.1% 7,216EU 021 Line 2 Current operations -16.9% 16.59 322 --- 912 16.9% 9,229EU 022 Line 3 Current operations -41.3% 17.26 322 --- 1,032 41.3% 7,404BBase(Wet PM Scrubbers)Energy EfficiencyProjects(stack test temp + flow)EU 020 Line 1 Current operations -46.1% 16.80 319 --- 720 46.1% 7,216EU 021 Line 2 Current operations -16.9% 15.61 315 --- 912 16.9% 9,229EU 022 Line 3 Current operations -41.3% 17.22 323 --- 1,032 41.3% 7,404EU #HTC Post-BART Modeling ScenariosPredicticted Stack Parameters and 24-hour Maximum Emission RatesTable 9:ScenarioScenario Control TechnologyProduction LineExit Temp(Kelvin)Stack Velocity(m/s)Stack Parameters Modeling Emission Rate InputSO2 NOxP:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx reductions from EERP\HTC NOx Reduction Calcs 2007-12-06 FINALTab 9 - Modeling Scenarios12/11/2007SO2 NOxClass I Areawith greatestimpact*Modeled 98%ile∆DV# days over0.5∆DVModeled 98%ile∆DV# days over0.5∆DVModeled 98%ile∆DV# days over0.5∆DVModeled 98%ile∆DV# days over0.5∆DV0Base(Wet PM Scrubbers)Base(Max = gas)BWCA 1.634** 73 1.638 64 1.604 52 1.609 189EU 020 Line 1EU 021 Line 2EU 022 Line 3ABase(Wet PM Scrubbers)Energy EfficiencyProjects(no stack changes)BWCA 0.926** 32 0.940 31 0.899 21 0.919 83EU 020 Line 1 Current operations -46.1%EU 021 Line 2 Current operations -16.9%EU 022 Line 3 Current operations -41.3%BBase(Wet PM Scrubbers)Energy EfficiencyProjects(stack test temp + flow)BWCA 0.540** 10 0.533 9 0.425 5 0.505 21EU 020 Line 1 Current operations -46.1%EU 021 Line 2 Current operations -16.9%EU 022 Line 3 Current operations -41.3%* Modeled values are from BWCA unless noted as Voyageurs in comments** Modeled values are from Voyageurs National Park2002-2004 CombinedHTC Post-BART Modeling ScenariosVisibility Modeling Results20032004Modeling Results2002EU #Table 10:ScenarioScenario Control TechnologyProduction LineP:\Mpls\23 MN\69\2369A60\WorkFiles\Job 002 - NOx reductions from EERP\HTC NOx Reduction Calcs 2007-12-06 FINALTab 10 - Modeling Results12/11/2007